1. Field of the Invention
The present invention relates to a dye-containing resist composition and a color filter using the same.
2. Description of the Related Art
As color filters for image sensing devices such as a charge coupled device (CCD) or a liquid crystal display device (LCD), etc. make possible to form fine patterns and therefore make possible to produce highly fine color filters, they are mainly produced by using a method of forming a pattern with a photoresist to which coloring matters are added. In this method, a resist composition comprising a coloring matter and a polymer resin is used, and a color filter is produced by repeating the following process for each color, in which the process comprises coating the composition on a substrate to form a film, patterning the colored layer with a photolithographic process, and developing to form one colored pattern.
In the method, coloring matters used as colorant generally include pigments that are excellent in heat resistance and light resistance, and a resist in which a pigment is dispersed is proposed. For example, Japanese Patent Laid-open No. Hei 4-163552 discloses a photosensitive coloring resin composition characterized by comprising a resinous material curable with an acid, a photoacid generator and a pigment, in which the resinous material comprises a resin containing phenol and a crosslinking agent having N-methylol structure.
However, as the pigments itself contain particles having a particle diameter of some tens nm to some hundreds nm, they have problems that dispersion is not stabilized and the pigments cause foreign matters (particles). Therefore, this makes difficult to produce color filters for CCD for which a high resolution is required.
On the other hand, when dyes are used as coloring matter, the dyes give homogeneous compositions as the dyes are soluble in organic solvents. Therefore, resist compositions in which dyes are used enable formation of fine patterns compared with a resist composition in which pigments are dispersed. For example, Japanese Patent Laid-open No. Hei 6-51514 discloses a negative type resist composition containing a resin material curable with an acid, a crosslinking agent, a photoacid generator, a dye and a solvent.